Women tend to develop presbyopia earlier than men because of the way they read rather than any difference in physiology.
A recent study in Investigative Ophthalmology and Visual Science looked at evidence from 15 different studies into the condition. The meta-analysis showed the earlier onset for women to be statistically significant. Further sub-analysis found that near add powers tended to be higher for women than for men of equivalent age.
Studies have consistently reported that women require reading glasses or bifocal lenses at a younger age than men.
The study concluded that the need for near vision correction was due not just to the loss of focusing ability but also to the habitual reading distance and depth of focus.
The authors suggested that occupation, indoor light levels, and specific conditions might underlie the sex differences.